Escapement with escape wheel with field ramps and non-return

A timepiece escapement mechanism comprising at least one resonator and at least one escape wheel arranged to cooperate with a said resonator mechanism through a stopper forming part of said escapement mechanism, wherein said escape wheel comprises a succession of tracks carrying magnetic or electrostatic field potential ramps, and said ramps are arranged to cooperate with said resonator or respectively with said stopper, wherein said escapement mechanism comprises at least one non-return device arranged to oppose the return of said escape wheel and said stopper cooperates, on the one hand, with a plate forming part of said resonator mechanism and, on the other, with magnetic or electrostatic field potential ramps by at least one pole shoe forming part of said stopper and arranged to move in the field corresponding to said magnetic or electrostatic field potential ramps, and wherein on said track each said ramp is extended by a magnetic or electrostatic field barrier, wherein immediately following said ramp said barrier has a first zone of rapid potential growth, the gradient of which is higher than the maximum gradient of said ramp, wherein said first zone is followed by a second zone of maximum potential, where the concavity of the potential curve is inverted in relation to said first zone, and said second zone is immediately followed by a third zone of decline in potential where the concavity of the potential curve is inverted in relation to said second zone and said third zone ends at a fourth zone of minimum potential.